A blood pressure meter is conventionally provided with a cuff pressuring an artery, a pressurizing means or pump to give pressure to the cuff, an air release means for depressurizing the cuff, and a blood pressure reading means. It is also necessary to inform the patient of the start of measurement, for this a buzzer is provided to sound immediately preceding the start of measurement.
FIG. 4 shows a flow chart of a conventional blood pressure meter. The patient, with the cuff in place around his upper arm pushes a start switch. It is then determined whether it is time for the blood pressure measurement to be taken (step 11). If the answer to step 11 is yes, the buzzer sounds (step 12) announcing to the patient that blood pressure measurement is about to begin. Thus the patient can assume a proper position for the measurement and remain still. At the start of the measurement, as shown in FIG. 5, both the slow release valve and the rapid release valve are closed, and the cuff is pressurized to a point higher than the Systolic blood pressure to block the flow of blood through an artery. Next the slow release valve is opened and as the pressure decreases the systolic and diastolic blood pressure values are measured by a blood pressure measuring unit (step 13). Upon completion of the blood pressure measurement the rapid release valve is opened to rapidly depressurize the cuff. Step 14 determines if the blood pressure is to be measured on a regular basis at given intervals of time, if the answer to step 14 is yes, the process described above is repeated.
In the conventional blood pressure measuring device the start, completion, or error of the measurement is announced by the sounding of a buzzer. A problem with this is that it does not enable the hearing impaired to realize that these events are taking place. Even healthy patients may have difficulties hearing the sounding of the buzzer due to noise in the environment. When the patient cannot hear the buzzer, measurement will seem to start suddenly without any indication to the patient. In other words there is a sudden feeling of pressure, which may cause movement of the patient due to the surprise of feeling the unannounced pressure. This movement may adversely affect the accuracy of the measurement. Further, with the use of a buzzer to announce the start of measurement, people around the patient are notified that the patient will have his blood pressure measured. This may cause undue nervousness or anxiety in the patient and in turn affect the accuracy of the measurement.